


A Sweet Treat

by SesuRescue (Kigachan)



Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, Daddy Kink, Dubious Consent, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Explicit Language, Explicit Sexual Content, Grillby is a brat, M/M, Rough Sex, Slight Hypnotism, Underfell Grillby referenced as Fellby, Underfell Papyrus, Underswap Grillby named Swirlby, sexual favors, underswap Grillby
Language: English
Status: Completed
Published: 2017-08-25
Updated: 2017-08-25
Packaged: 2018-12-19 22:42:38
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,294
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11907717
Author URL: https://archiveofourown.org/users/Kigachan/pseuds/SesuRescue
Summary: Edge, looking for Red, comes across a peculiar fire elemental during a candy sale.





	A Sweet Treat

**Author's Note:**

> Guess what was supposed to be a drabble? This. Guess who wrote way more than they were supposed to? This writer, right here! 
> 
> Ever get so excited about writing a ship or character that you sort of lose yourself and write 2k words in under 24 hours? ....Y-yeah, me neither. Anyway, here's some UF!Papyrus x US!Grillby

Edge huffed as he trekked through Hotland, pulling at his shirt to unstick it from his bones. Where the fuck was Sans-wait, no, he had to call him Red now. Fucking multiverse. In either case, where the fuck was Red with the house keys? He looked for him at the Ash Trash’s house, that weird bar with the spider woman, he even looked for him in the Echo flower field. Everywhere he went, Red was nowhere to be found, and Edge just wanted to go home. He hated this backwards ass universe, with its sweet residents and the swapped places. He just wanted to be where things made sense again for a bit, was that so much to ask for?

Luckily, Blue gave him a tip that Stretch was selling tickets for a Napstabot concert tonight, and it was likely that Red would be there to keep him company. He was...unsure how he felt about Ash Trash getting all chummy with his brother. He was a Papyrus, sure, but he was much more like Red than to him or the Cream Puff. Maybe Red liked him better because of that…?

Edge stopped, shaking his head. This really wasn’t the time to get sappy, he had to pay attention to what he was doing here. Trudging forward, Edge’s heels clacked noisily against the hard surface, echoing off the walls. It was...too quiet here, and he didn’t like it. Not wanting to be here any longer than necessary, Edge broke into a run, hoping to get to the NTT Stadium sooner rather than later.

After a short while, something appeared on the otherwise bare horizon, a small...table? Edge slowed, conjuring a small bone behind him. As he got closer, he noticed a fire elemental sitting at the table, doing something with their hands. Their clothing seemed loud from a distance, bright colors clashing with their otherwise muted surroundings.

Before he could process this new threat, the monster turned to face him, mouth wide in a smile. “Hello dearie~! Please, come see my wares~” The monster chimed, waving him over.

Edge approached the table warily, bone still behind his back. The table was small and plain, with jagged, clear objects sitting on a cloth. There was a sign tacked to the front that read:

**Swirlby’s candy sale! Made by fire ants, for fire ants, of fire ants. All proceeds go to help real fire ants.**

This elemental must've been Swirlby so the items were...candy? He kept the strange fire elemental in his peripherals as he picked up one of the pieces of candy, turning it around in his hand.

This Swirlby looked like the Fellby from his universe, except this one’s overall demeanor and appearance didn't fit his universe at all. Wearing a light blue tuxedo, with a yellow shirt and a pink bow? Fellby wouldn't be caught dead in that. As if that wasn’t enough, he donned a pair of swirled glasses on his face, making him seem more like just another eccentric creature of this universe. He most likely wasn’t a threat to Edge.

With a small _pop_ , Edge dispelled his weapon, focusing his attention back to the object in his hands.  It was small and unassuming, crystal-like in structure.

“Rock candy?” He asked.

“Yes, each piece is made lovingly by hand~ Please, try it~”

Edge suddenly wondered if it were possible that the candy was poisonous; maybe this monster was trying to kill him. He sighed to himself, cursing his violent thoughts as he brought the candy to his mouth. He was being preposterous, no one in this universe had any killing intent, especially this ‘Swirlby’. He probably couldn’t even damage a moldsmal.

The flavor of the candy hit him like a truck, making him stumble back slightly. It started out sour, but as the candy sat on his tongue, it transformed to something much more sweet and delectable, like a ripe berry. He finished the candy much too soon, almost drooling as he looked at the rest of the candy on the table. Swirlby chuckled, an airy crackle coming from his mouth as they watched Edge.

“Did you like it~?”

“That was...probably the most delicious sweet I’ve ever eaten. I have to have more.”

“Of course, dearie~ As soon as you’ve paid, you can have as much as you want~”

Edge glared at the monster, mulling over what he said. “You mean, that wasn't a free sample?”

“Oh no, that was my most expensive piece~” Swirlby’s giggled, a small hint of a sadistic grin flashed on his face. “That'll be 9999g, if you please~”

HOW much?! That was ridiculous! Edge wasn't going to pay that much for such a small piece of candy. He summoned a sharp bone, tossing it through the air towards Swirlby, stopping it right before it hit him. The elemental gasped lightly, hand covering their mouth in shock.

“Let me have it for free, and I won't dust you where you stand.”

If there was anything Edge had been expecting Swirlby to do, it wasn’t to start giggling again, harder than before. He wiped at his eyes underneath his glasses.

“You're so feisty~ I think I'm going to have fun with you.”

Before Edge could ask what the fuck he was talking about, Edge was suddenly drawn to the elemental’s glasses, the swirls spinning wildly in their frames, seducing him. He tried to shut his sockets, dim his eye-lights, anything, but he couldn't help but follow the movements, his thoughts a mess of static the more he watched. Distinctly, he heard a small voice, telling him to _sleep_ , and it seemed like a great suggestion. Edge slumped over, his body plunging towards the ground. Before he lost consciousness, he could’ve swore he felt a warm body catching him before he hit the floor.

* * *

 

When Edge woke up, the first thing he noticed was that it was much, much hotter than the area he was in before. Did someone move him?

He attempted to sit up, surprised by a lack of anything holding him down as his vision slowly came into focus. He seemed to be in a large cavern of some sort, sitting in the middle of a rather wide circular rock column that was slightly higher than the large pool around it. The walls of the cavern were made of solid rock, and the pool, upon further inspection, was magma, lapping lazily against the walls.

A metal object hit the ground behind him with a _clang_ , crackled laughter accompanying it.“Oh, you're awake, dearie~”

Edge turned sharply, scrambling to his feet to face his foe, the same strange elemental from earlier. He was sitting cross-legged on a light floral blanket, pouring red-tinted tea from a kettle.

“Where the fuck are we?” Edge demanded.

“We're in a small chamber, hidden from the rest of the underground. I guess you could call it my bedroom~” Swirlby grinned, taking a sip from the cup. “I figured, since you can't pay with gold, we could always try...a different way to pay~”

The implications of Swirlby’s suggestion hung in the air as Edge pieced together what he meant. He wanted Edge to pay in sexual favors?

Eying Swirlby up and down, there was no way that this monster wasn’t a bottom, which worked perfectly for Edge, if it came down to it. The speech pattern was a little weird, but he was attractive enough that he could work with it. However, he couldn't give in too easily to his desires. Swirlby was still a threat, holding him here and keeping him away from finding Red.

Edge stomped over to Swirlby, grabbing him by the bowtie and making him choke as Edge yanked him up to full height. His cup fell off his lap, falling to the floor with a clatter and spilling the tea out onto the blanket. Before Edge could open his mouth to let out any threats, Swirlby moaned loudly in his grasp, clutching Edge’s phalanges with his hands.

“Oh~! Please, harder Daddy~!”

“What.” Edge deadpanned. Despite himself, his magic started to coalesce in his pants. Disgusted, whether at himself or the other, he let go of Swirlby, letting him fall to his feet in a small heap.

Swirlby giggled, kneeling so that he was crotch height and rubbing his hand against Edge’s pants. “You're a total Dom, I can smell it~ Punish me, and then you can leave~”

The thought of punishing this brat was very appealing to Edge, and the promise of letting him leave had him summoning his cock, leaving a bulge in the front of his pants. He was sure that if he could see Swirlby’s eyes they'd have stars in them, judging by the way he started rubbing his face against it.

Not wanting to wait, Swirlby unzipped Edge’s pants, gasping as the thick cock sprung out and hung in front of him, weeping precum.

“How did you know my favorite color was red~?” Swirlby teased as he licked the tip of Edge’s dick.

Edge groaned, grabbing Swirlby’s head and pushing his cock in deeper, hissing as the heat of his mouth hit him. Holy shit, his mouth was like heaven, moist somehow without having saliva and so warm that his dick felt like it was melting.

Swirlby gurgled happily around the length, wrapping his arms around Edge’s hips and pulling him forward, thrusting the cock further down his throat.

“F-fuck!” Edge dug his phalanges in deeper to Swirlby’s flames to distract himself from coming too soon. “I'm not going to last much longer if you keep doing that,” Edge warned, pulling Swirlby off his cock.

Coughing, Swirlby gulped down air, gazing up at Edge’s face with desire. “Your cock is so thick, I can't wait to take it~” He started to undress, unbuckling his belt first and kicking off his pants before moving onto his top, shedding his shirt and suit jacket.

Soon enough he was on his hands and knees, bare except for his pink bowtie around his neck. Edge swore to himself, taking in the way Swirlby’s flames cascaded over his body, pulsing in complex patterns and changing to different shades of red and orange. He rested his hand around his cock, lazily stroking it as he watched Swirlby prepare himself with his fingers, the moans coming from the elemental’s mouth making him harder.

Swirlby pulled his fingers out of his entrance, cock bobbing as he spread his ass cheeks with his hands, presenting himself to Edge. “I'm ready, Daddy~ Please fuck me with your thick cock!”

Edge strolled over to Swirlby’s prostrate form, kneeling and thrusting into him in one shot. Swirlby arched his back as Edge pushed his dick fully into him, pausing to let Swirlby get acclimated. He might be a dick, but he wasn't a complete jerk.  However, it didn’t seem like Swirlby appreciated the sentiment.

“Don't stop, just fuck me~!” Swirlby cried, grinding on Edge’s cock.

Cursing, Edge tightened his hold around the fire elemental’s hips, rutting against him. Swirlby was...enthusiastic, Edge would give him that. He met every thrust of Edge’s hips with his own, pushing the cock deeper inside. This man really was a slut for cock.

After a while, Swirlby started to slow, throwing Edge off his guard. He was silent as he stopped, looking over his shoulder to Edge with a pout on his face. Edge was confused, had he done something? Did he accidentally hurt him?

“What's wrong?” Edge asked in a gruff voice, slightly concerned, but not willing to show it.

“You know...having a thick cock doesn't mean shit if you don't know how to use it~” Swirlby replied bluntly.

Edge fumed, magic boiling as he pulled out of Swirlby and picked him up, slamming him onto his back. Didn't know to use it, his nonexistent ass! He dragged Swirlby’s legs onto his shoulders, ignoring his keening sounds as he slid back into Swirlby’s ass. He set a brutal pace as he pounded into him, guided by his anger.

“That's it, Daddy, fuck me~! I'm so close~!” Swirlby screamed, ass starting to spasm on Edge’s dick.

Suddenly, Swirlby tightened, shouting as cum exploded from his dick, covering himself and hitting Edge as he climaxed. Edge tried to hold on a little longer, but the intense heat and tightness of Swirlby’s ass had him cumming, coating his walls with the release.

Edge pulled out, placing Swirlby’s legs on the ground as he buttoned up his pants. The fire elemental laid blissfully in front of him, mouth wide opened in a large grin as he panted. Placing his heel on Swirlby’s chest, Edge regarded him coldly.

“Tell me how to leave.”

Swirlby pointed to his left. “There's a small stone way off the edge of the column over there~ Usually I like to see guests off but, you don't mind, do you dearie~?”

Instead of answering, Edge took off towards the way Swirlby directed him, indeed seeing a small walkway leading to a nearly hidden hole in the rock of the stone walls.

“Come back and visit me soon~” Swirlby called.

* * *

 

Edge made his way through the winding stone, finally escaping the labyrinth and coming face to face with Red and Stretch.

“boss? what’re you doing here? and what happened to yer face?” Red asked. Edge reached up toward his face absently, tracing what seemed to be molten rock along the bottom of his mandible. That fucking…

“warm soap and water.” Stretch interrupted, voice low. Edge turned, ready to yell at him, when he noticed the deep understanding set in Stretch’s face.

Giving Stretch a curt nod, Edge grabbed the hood of Red’s jacket and directed him in the direction of Snowdin. “Let's just go home.”

**Author's Note:**

> Whew, I had a lot of fun writing that! It might've ended up a little kinkier than I imagined, but there we are. Seriously, stop leaving me alone with my thoughts, all I do is end up writing Papby.
> 
> Feel free to come yell at me/give advice/scream about your OTP/show me cat pictures at my tumblr (nsfw): [Sesurescue](http://Sesurescue.tumblr.com)


End file.
